John, I just had the opportunity to read your piece about the 280 Ackley Improved and I enjoyed it. If the 280 AI is arguably better than the normal 280 Rem. doesn't it also stand to reason that the 270 AI would be equally as much better than the 270 Winchester ? I find it curious that with such a small number of 270 variants that there is not an equal cry for the 270 AI as has developed for the 280 Rem.

While I'm not Mule Deer, I have looked at this too.

I agree that there is probably some similarly 'unlocked potential' in having a 270AI like there is for a 280AI.

From what I've read, people who've made the switch are getting 75fps more, all else being equal. That takes a 270, 140gr. bullet to 3100+fps or a 110tsx to over 3350fps!!

Here is one poster here that has one:
There are others on the long-range forums that have made the switch.

I think that the 270AI may gain in popularity as both bullets and powders make it more versatile from everything from coyotes to trophy deer to Elk and Moose; only better than the original 270Win.

I'd also stand in line to pay for an article with 270AI load data!!

Dude,

They already make a 270 improved,it's called the 280 Remington.

Britt

One of the reasons the .280 Improved got such a great reputation is that the original factory ballistics for the .280 itself were pretty wimpy. Thus increasing case capacity in the AI AND loading to higher pressure combined to make what manyh people consider a signficant increase in muzzle velocity.

The .270, on the other hand, has almost always been pretty well loaded to top practical pressures by the factories. Thus an AI version wouldn't show much increase in muzzle velocity.

Rolly,

I agree with you thought process on this and I have a .270 AI build in the works. If nothing else, I want something very unique just so I can hear all the guys say "you are shooting what????"

Mule Deer, I'm just trying to understand.... why is it then that people who have them are getting 75fps more velocity without much effort? Or in the case of the poster that I quoted, 150fps more?

Honestly, what would you think would be a realistic velocity gain based on your experience? If getting 3150fps with a 130gr bullet, why would it not be entirely possible to get at least 3225fps?

Is there a software program or can you guess at what the powder increase would be from doing a 270AI? This would corroborate for us what are the real world velocities...

I'm just really curious....seems that there is a cult following of the 280AI, yet, with smaller bore diameter and an increase in case capacity that it's entirely possible to wring out as meaningful a velocity increase (75fps or so) from our lovely 270 Win by going to 270 Ackley Improved.

Thank you.

Saeed had a custom one built:



One top load from him claims to be:


So, with a 22" barrel, I can only get about 2970fps with 140gr bullets. Even adding about 30fps/inch for his 25" barrel, his 270 ACKLEY IMPROVEDvelocities exceed the standard 270 win. load by over 100fps!??

Some one explain this to me....but it seems that the 270AI has the same or better performance increase that a 280AI has over a handloaded 280rem ?! If so, why aren't more people doing it?

Brooksrange

You will gain less than 5% in case capacity improving the .270 Win. Feeling free to jump from 58 grains of RL 22 (Nosler #6 max) to 66 grains of RL 22 with a 130 is a perfect example of why some people should not be allowed to own or use an improved cartridge. Should not be allowed to handload or handle sharp objects for that matter.

Brooksrange,
I have looked through some of the loads on the AR forum and was pretty impressed with their velocities. But upon closer reading, realized that their loads are pretty warm. I don't think I would run some of their loads in my guns. For instance, they show a load of 83.5 grains of RL22 for a 165 grain Ballistic tip in a 300 Winchester Mag. Nosler shows a max load of 79 grains of the same powder with the same bullet. I've run the Nosler load in my rifle and was getting pressure signs.

The reason I went with a 280AI, other than improved velocity, was bullet selection. There is very little difference between the 270's and the 280's except for the greater selection of .284 bullets.

I would like to see a 270-284! I know there is not much difference between .277 and .284 but I just like the 270!

How do you improve on perfection?

.270 WSM boys and girls it is everything you are looking to get from the .270AI and another 25-50 fps to boot.

I had a .458 Win. Mag Ackleyrized once, once. Looking back it doesn't seem worth the bother.

"Honestly, what would you think would be a realistic velocity gain based on your experience? If getting 3150fps with a 130gr bullet, why would it not be entirely possible to get at least 3225fps?"

I'm not Mule Deer, but claiming to get 3150 FPS from a 130 grain bullet and actually getting it might be two different things.

My experence with a .270 is entirely different. Try reducing that velocity by 200 FPS and you might be in the realistic range.

3150 is no sweat in a .270 with 24" barrel. Been that way for 80+ years now.

Lou

If your going for a wildcat, wouldn't Rocky Gibbs 270 give you a little more case capacity and performance over the Ackley? If I remember right, Rock's goal was to achieve the most FPS the 270 case was capable of.

Doc

Mule Deer and fellow rifle loonies,

There seems to be evidence of a GREATER gain in Velocity of a 270 ACKLEY IMPROVED over the 257 Roberts Improved!!

Velocity gains of at least 100-150fps!!

Se below quote from another forum:



This was a big AHA moment...seems to me there is enough of a gain for the 270 ACKLEY IMPROVED to be worthwhile.

Is this your take on all this information? Seems to be more momentum of facts supporting a 75fps to 100fps velocity gain at a min.

I'd love to up the performance level of my 270 Win. Imagine shooting 110gr TSX at 3350-3400fps or 130 gr Noslers at 3225FPS or 150 GR TSX for Elk at 3050 FPS!!! Talk about a coyote to Deer to Elk rig at a moments notice!

I agree with Lou tht if you want more velocity out of a 270 put a 24" bbl on it. My Rem 700 gets 3180 consistently w/ 130 Accubonds and sub MOA (61 gr. H4831) Granted, it's a warm load but I don't have to AI.
All that said, I'm in the middle of building a 280AI sheep rifle. Seems like an ideal balance of rifle weight, shootability,
velocity etc.
just my .02.
sbsmith

LOL, how would that work?

AI `ing a cartidge has benefits beyond the difference in MV.Longer case life,less trimming.Velocities in Reload Manuals are seldom attained in the Parent case or the AI.Just having some thing differnt, has its way cool factor!!!!

Have new powders made the 270AI a better performer now?

Never had a 270AI, but can't help but wonder what the standard 270 is capable of with a 25" barrel and 140 TBBC; or 130 TTSX for that matter (?) 270AI beat the standard? Sure,,,by baby increments.

It's been established for decades that the 270 Winchester is capable of taking the same plains game on that list as the 270AI or the 280 AI''.My old buddy RinB on here has taken well over 200 head of African plains game with the standard 270 from eland on down using 130 TSX,130 SS, 130 Aframe,130 Bitterroot and others I forget.

I think Colmacivor on here has piled up a bunch of African game with the 270AI in Africa and think he is way over 100 head but maybe he will pop up and comment.

But the reason I won't do the 270 or 280AI "thing" is the 7mm Rem Mag in the same action length and barrels which leave the 270AI,280AI firmly in the dust with anything 140-175 grains. That's only been stealing the show since 1962 or so. I always figure the first thing you gotta do to be a 280AI fan is ignore the 7 Rem Mag.

I leave the standard case 270 and 280 in the shorter 22" barreled sporter and chamber the longer 24-25" barrel for cases with more capacity than a blown out standard case... like the 7Rem Mag or Mashburn. There are others....Dakota, Weatherby etc etc They give the velocity without breaking a sweat.

If i am going to beat a 270 or 280 I'm not going to try to make the lighter bullets eke out another 100 fps. I'm going to grab more capacity in meaningful amounts and make the heavy 7mm bullets go as fast or faster. If there's a performance edge to be had, the heaviest 7mm bullets 160 gr and up is where it's at. Go big or stay home.....

.277 vs .284
really?

.277 vs .284
really?

No.

There is a whole lot of common sense in Bob's post.

Bob always shares lots of common sense. I think the Classic, powerful 270 Winchester is awesome and the 280ai is for those who lack good judgement on buying a 7mm

The cartridge improvement in question was actually a 270 JDJ, not the typical AI formation. Thus the case held more powder. I am not familiar with the Gibbs improvements. But, I believe it was said the JDJ & Gibbs version were nearly identical.

I am almost grown at age 57 & own many sharp objects.

THe 66 gr load was perfectly safe in my gun. The cases were cycled at least 10 times each & they are still ready for more.

If speed with light bullets is your goal go with the 270 I.C.L Jaguar, developed in the early 1950s by Vern Juenke in his fine Saturn rifles. He long throated them and used a very slow twist to gain maximum velocity.

I had a Saturn in 25/270 I.C.L Ram that I used to take my desert bighorn back in the day. It got honest 3,700ish FPS velocities with 100gr bullets over 59.5gr of 4350. It shot little bugger holes with hot loads. That was Vern's goal. I was fortunate to be a neighbor of his when I was a kid.

270 Weatherby comes to mind

Yep.

As always...

DF

And, for good reason. I have spent way too much effort on 7 RM's trying to get consistent results from them. One day they shoot, the next day they won't. Much prefer the 280's, regular or improved.

Beyond that I am a 7 Wby fan. Never had trouble with consistency from any of my several 7 Wby's.

Frankly, if your mind is already made up, go do it. Stop trying to get permission via getting others to buy into your BS. On the other hand, if you are honestly asking for information, then listen to the answers.

Seems simple.

The answer about the factory pressures of the parent .270 Win and .280 Rem relative to AI-ing them is correct. Much of the .280 AI's gain comes from increased pressure, not just increasing capacity. The .270 Win is already at safe max pressure so that source of gain is not available to you.

If you want a little more in either diameter, sure, AI, but if you're truly after BIG gains, go with a big case. .270 WSM or .270 Weatherby, or 7mm Rem Mag or 7mm Weatherby.

It really is a no brainer unless you have no brains.

Tom

RL: Yeah...they can be finicky.

Although I have had less trouble with them in recent years with more powder/bullet options etc. They have become pretty routine.

My most recent one stays MOA or less to 600 yards with both the 162 Amax and 150 BT in front of RL25. Like falling off logs any more.

I got about 1000 rounds of new brass. Life is good and trouble free.


This one dotes on 140 AB's and 68-69 gr RL22 for about 3200. I am GTG.

Tom,

I don't actually think Rolly is worrying about this anymore, since starting this thread in 2008. Like a lot of Campfire members, he probably went "in another direction" anyway within six months.

Bob, that one of the fancy "Super Grades"?

True, but I never get tired of reading Bob's opinions on the 280 AI.

Funny...I get tired of your stuff real quick. Mostly useless ankle biting nonsense.

Doh! Missed that. Back to my previously scheduled nap.

Not your fault Rolly has ADD Tom.

Ankle biting? That's a new one. At least it's better than ankle-grabbing.

Who digs up a thread that is 8 years old??

As an aside, I have an acquaintance that has built a whole bunch of 270AIs and taken them to Africa on cull hunts. He can hunt with (and does) any caliber there is yet keeps going back to the 270AI. He spends well into 6 figures a year on guns and loves this one the most!

There was another thread maybe 3-4 years ago, where a guy was going to Africa for a year, as I recall to teach school. He wanted to take a practical plains game rifle, as he couldn't afford to hunt any expensive game. He was trying to decide if he should buy a Mark X Mauser .30-06, and if so what he should do to the rifle as far as ammo, modifications, scope, etc. He wasn't exactly a RCRL (Real Campfire Rifle Loony) but knew some stuff.

Of course, the thread went on and on, with RCRL's arguing back and forth, and everybody failed to notice that somewhere along about Post 1000 the guy said he'd bought the rifle and mounted a scope, it shot well, and he was headed to Africa. The thread went on and on and on., being revived at least once long after he would have been back from his year over there.

Dang, I wanted to hear more about the pitfalls of the 280 AI, and now you've ruined it.

Sorry!

How about this: Am in the final stages of putting together a real 700 "parts gun" in .280 AI. It involved a little more than the standard bolting on a stock and screwing on a barrel, because the action didn't have a bolt, and when I did scrounge a bolt from a gunsmith friend, it didn't have anything on or inside it except the extractor. Plus, the bolt was for a very early 700, without the guide-rib, but the action had the guide-rib. Oh, and I had to take the old (and pitted) barrel off the action....

How's that for pitfalls? And the thing still isn't quite done. But it will be a real deal, unless you count my "gunsmithing" time.

When you could save yourself some time and money if instead of AI-ing a .270Win., just get 50 feet closer.

The reason I like the 280AI has more to do with the Kimber 84L platform than anything else.

Melvin can probably make a 7RM that light, and that feels that good, but not many others can.

The performance is close enough to the 7RM to satisfy me, in a rifle that handles and feels that good.

Obviously, you had a different objective MD

Edit: yes, I have a 7RM and a 270 too

Yeah, I did. The barrel is a Douglas stainless, chambered by the late Mickey Coleman. I knew Micky pretty well, and always meant to have him build me a rifle, but then it was too late. So I'm putting the rifle together around the barrel. I really don't care much about the .280 AI one way or the other, but wanted a barrel marked Coleman Rifles.

For a really light, accurate rifle I have a NULA .30-06, otherwise known as the .280 AI Really Improved.

Thats cool a Mickey Memorial Rifle. I like it.

It's the original, a jack of all trades . . . . .

I understand that there is no magical velocity gain in the 280ai. It holds a slight amount more powder than the 280 Rem and is commonly loaded to higher pressures. As a result it produces slightly higher velocities for the same bullet. Many think that the 280ai is more accurate than the 280 Rem when pushed to near max pressure. Is this an urban myth or could it often be the case?

It might often be the case that an AI is built with a custom barrel, and precision follows.

Here's one of those temperamental 7 Rem Mags that are so hard for people to get to shoot. And with those inaccurate Partitions no less.

There are some advantages to an improved cartridge beyond velocity. There are equally as many disadvantages. In my limited experience with a few 260 Remingtons, in every case they became noticeably more accurate with the rechamber job. Brass seemingly lasts forever but there is that tick-in-the-armpit called fire-forming.

Never owned a 270AI but it should be just fine.

Does AI'ing a .270 make it more, or less, gay?








I say more

Gotta love that - 110 years old and still the standard!

Bob,sell that AWFUL shooting 7mm RM!

elkhuntr: I could sell it tomorrow and built another one just like it...would do the same things.

Ain't hard.

I got a PM from Rolly.

He's decided to go with the 7 RM.

mathman,

One of my magazine editors told me a story years ago, about another gun writer who claimed the .308 Norma Magnum was by far the most accurate .30 caliber magnum he'd ever used, saying shot extremely well in three different rifles. (Of course, this was before the .300 WSM appeared, or any other alphabet magnums.)

The editor asked the guy for some details, and it turned out all three .308 Normas had been customs, while most of the writer's other .30 caliber magnums had been factory rifles.

I guess everyone can at least agree that a 280ai at least gets a few more fps than the 280 Rem. I think that I remember Mule Deer or someone else credible stating that the 7rem mag can have some weird pressure spikes vs. other similar cartridges. Could be wrong. I had a 280 AI done by Jim Borden. He suggested that I just go with a 7 Rem Mag. Having read much rifle mythology, I was concerned about the belted case not being as accurate. Jim said that was bunk. I did not discuss the pressure spike issue/myth with him. At the end of the day, I like the rifle and cartridge. The 30-06 and 270 together probably completely fill the mid sized game niche perfectly. Moving on, I have now been sucked into the 6.5x47 Lapua trend.

I still believe that the 280 AI " goes to 11 which is higher than 10".

Well the AI allows 70,000 PSI

Then you can get amazing results. Much better than the lowly standard cartridges.

True,had two 7mm RM and never had a problem with them not shooting good. Not as good as your's does,but good enough to kill big game with them. Also using those in-accurate NP's to boot.